A technique of operating a conventional copying machine or the like is disclosed in, e.g., Japanese Patent Laid-Open No. 11-175225.
A copying machine disclosed in this reference reads an IC card or magnetic card which holds ID information representing a user. The digital combined apparatus can identify the user and allows the user to use it. This copying machine performs charging management for each user on the basis of the read ID information.
A user registers address information such as an E-mail address or FAX number in the copying machine, and another user can use the address information.
The conventional copying machine suffers the following problems.                (1) When address information is saved not in the copying machine but in the IC card or magnetic card of the user, another user cannot use the address information and has to input the same address information to the copying machine.        (2) When address information is saved in the copying machine, the address information may be used by another user who should not use it, violating the privacy.        (3) If an IC card or magnetic card is stolen, an “unauthorized” user may use the copying machine to charge the authentic user.        (4) When the user wants to transfer a file in a user's client personal computer (to be referred to as a client PC hereinafter) to the copying machine and print out the file outside his/her home, he/she cannot easily refer to an address book registered in the copying machine on the client PC. Even if the user can use the address book, the address book may be known by a third person, resulting in poor security.        